想在一个windows server 2008中搭建vpn服务器，但是系统自带的貌似要公网ip，我不知道那台服务器的公网ip。
最好我想使用一款软件，能够在服务器和客户端中安装并使用。我试过openvpn，但是服务器端的build-ca老是出错。
我试过popvpn，虽然认证成功了，但是隧道总是不通。
系统自带 + 花生壳 ，花生壳来提供域名解析的问题。用域名对外服务，不直接通过IP
看这里,系统自己建立VPN服务器
To configure a remote access VPN server, start the Add Roles Wizard by doing either of the following:
• In the Initial Configuration Tasks window, under Customize This Server, click Add roles. By default, Initial Configuration Tasks starts automatically when you log on.
• Open Server Manager by clicking Start, Administrative Tools, and then click Server Manager. Then, under Roles Summary, click Add roles.
In the Add Roles Wizard, do the following:
1. Click Next or click Select Server Roles.
2. In the list of server roles, select Network Policy and Access Services. Click Next twice.
3. In the list of role services, select Routing and Remote Access Services to select all the role services for Routing and Remote Access Services. You can also select individual server roles.
4. Proceed through the steps in the Add Roles Wizard to complete the installation.